Field of the Invention
The present invention relates to a tyre building plant in which an elongated element is supplied to a forming drum by means of a supply device including a conveyor belt.
The invention further relates to a method for supplying an elongated element to a forming drum in a tyre building plant.
Description of the Related Art
A tyre generally comprises a carcass structure which is torically formed about an axis of rotation and which includes at least one carcass ply which has axially opposing end flaps which engage in respective annular anchoring structures, generally known as “bead cores”, which are integrated in the zones usually identified as “beads”.
In a radially external position with respect to the carcass structure, there is provided a belt structure comprising one or more belt layers which are arranged with radial superimposition with respect to each other and with respect to the carcass structure.
The belt structure can further comprise, in a radially external position, at least at the ends of the belt strips below, a layer of textile or metal cords which are arranged circumferentially (at 0 degrees). In tyres of the tubeless type there is further provided a radially internal layer which is referred to as a liner and which has impermeability characteristics in order to ensure the air-tightness for the tyre itself.
In a radially external position with respect to the belt structure, there is applied a tread band which is produced from elastomer material and on which there is defined a tread pattern which is intended for contact with the road surface.
In an axially external position, respective sidewalls of elastomer material are further applied to the lateral surfaces of the carcass structure, each extending from one of the lateral edges of the tread band as far as a location at the respective annular anchoring structure for the beads.
A process for producing tyres provides for a first tyre building step, in which the various components of the tyre, including those set out above, are assembled in a building plant so as to obtain a so-called “green” tyre, and a subsequent moulding and vulcanizing step, where the green tyre is subjected, for a predetermined time period, to temperature and pressure values so as to vulcanize the elastomer material of the components thereof, obtaining the final structural stability of the tyre.
In greater detail, there are known processes in which the building step provides for the production of one or more structural components of the tyre by means of depositing one or more elongated elements on a cylindrical surface (which may be the external surface of a forming drum or the external surface of a semifinished product of the tyre which is already deposited on that forming drum) rotating about its own axis.
Those elongated elements are deposited on the forming drum by means of a supply device which is provided to take the elongated element in continuous form, for example, from a storage reel, cutting it to the desired measurement and, by means of a conveyor belt, dispensing it at a predetermined speed to the forming drum in a direction tangential to the external surface thereof.
US2013/0160930 discloses a method for applying a ply to a forming drum for building tyres. The method comprises the steps of receiving the sheet of flexible material on a conveyor belt of a transport table, in which the conveyor belt can move in translation in a direction X, and provides for a plurality of rollers which are mounted in a rotatable manner on the conveyor belt so that they can rotate with respect to an axis aligned with the direction X.
US2003/0019725 discloses a material guiding system with a conveyor belt type system on which a strip of belt reinforced with cords is transported as far as a specific cutting line, the transport system for the belt comprising a plurality of conveyor belts or groups of conveyor belts which can be controlled individually.
The term “elongated element” is intended to be understood to be an element having a longitudinal dimension which is prevalent with respect to the remaining dimensions. Preferably, said elongated element is constituted only by elastomer material or comprises elastomer material in which there are embedded additional structural elements.
Preferably, the elongated element is formed in a strip-like manner with a flattened cross-section. Preferably, the additional structural elements comprise one or more textile or metal reinforcement cords. Those reinforcement cords are preferably arranged parallel with each other and preferably extend in the longitudinal direction of the same elongated element.
The term “light radiation” is intended to be understood to be electromagnetic radiation having a frequency in the range corresponding to the regions of visible light, infrared and ultraviolet.